postgres.git / summary / log / commit / refs
commit 76a39f2295ecb040f2ea052320941e1eb9b526c0
Author: Peter Geoghegan <pg@bowt.ie>
Date: Mon Apr 01 00:24:04 2019 +0000
First released in: 12.0
Fix nbtree high key "continuescan" row compare bug.
Commit 29b64d1d mishandled skipping over truncated high key attributes
during row comparisons. The row comparison key matching loop would loop
forever when a truncated attribute was encountered for a row compare
subkey. Fix by following the example of other code in the loop: advance
the current subkey, or break out of the loop when the last subkey is
reached.
Add test coverage for the relevant _bt_check_rowcompare() code path.
The new test case is somewhat tied to nbtree implementation details,
which isn't ideal, but seems unavoidable.
src/backend/access/nbtree/nbtutils.c | 3 +++
src/test/regress/expected/index_including.out | 21 ++++++++++++++++++++-
src/test/regress/sql/index_including.sql | 8 +++++++-
3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c
index 92b8b5f134d..140ac920265 100644
--- a/src/backend/access/nbtree/nbtutils.c
+++ b/src/backend/access/nbtree/nbtutils.c
@@ -1543,6 +1543,9 @@ _bt_check_rowcompare(ScanKey skey, IndexTuple tuple, int tupnatts,
*/
Assert(ScanDirectionIsForward(dir));
cmpresult = 0;
+ if (subkey->sk_flags & SK_ROW_END)
+ break;
+ subkey++;
continue;
}
diff --git a/src/test/regress/expected/index_including.out b/src/test/regress/expected/index_including.out
index 77ec29f2a33..2405709f409 100644
--- a/src/test/regress/expected/index_including.out
+++ b/src/test/regress/expected/index_including.out
@@ -126,7 +126,7 @@ DETAIL: Key (c1, c2)=(1, 2) already exists.
INSERT INTO tbl SELECT 1, NULL, 3*x, box('4,4,4,4') FROM generate_series(1,10) AS x;
ERROR: null value in column "c2" violates not-null constraint
DETAIL: Failing row contains (1, null, 3, (4,4),(4,4)).
-INSERT INTO tbl SELECT x, 2*x, NULL, NULL FROM generate_series(1,10) AS x;
+INSERT INTO tbl SELECT x, 2*x, NULL, NULL FROM generate_series(1,300) AS x;
explain (costs off)
select * from tbl where (c1,c2,c3) < (2,5,1);
QUERY PLAN
@@ -144,7 +144,26 @@ select * from tbl where (c1,c2,c3) < (2,5,1);
2 | 4 | |
(2 rows)
+-- row comparison that compares high key at page boundary
+SET enable_seqscan = off;
+explain (costs off)
+select * from tbl where (c1,c2,c3) < (262,1,1) limit 1;
+ QUERY PLAN
+----------------------------------------------------
+ Limit
+ -> Index Only Scan using covering on tbl
+ Index Cond: (ROW(c1, c2) <= ROW(262, 1))
+ Filter: (ROW(c1, c2, c3) < ROW(262, 1, 1))
+(4 rows)
+
+select * from tbl where (c1,c2,c3) < (262,1,1) limit 1;
+ c1 | c2 | c3 | c4
+----+----+----+----
+ 1 | 2 | |
+(1 row)
+
DROP TABLE tbl;
+RESET enable_seqscan;
CREATE TABLE tbl (c1 int,c2 int, c3 int, c4 box,
UNIQUE(c1,c2) INCLUDE(c3,c4));
SELECT indexrelid::regclass, indnatts, indnkeyatts, indisunique, indisprimary, indkey, indclass FROM pg_index WHERE indrelid = 'tbl'::regclass::oid;
diff --git a/src/test/regress/sql/index_including.sql b/src/test/regress/sql/index_including.sql
index c0ae71d0cbd..7e517483adf 100644
--- a/src/test/regress/sql/index_including.sql
+++ b/src/test/regress/sql/index_including.sql
@@ -72,11 +72,17 @@ SELECT pg_get_constraintdef(oid), conname, conkey FROM pg_constraint WHERE conre
-- ensure that constraint works
INSERT INTO tbl SELECT 1, 2, 3*x, box('4,4,4,4') FROM generate_series(1,10) AS x;
INSERT INTO tbl SELECT 1, NULL, 3*x, box('4,4,4,4') FROM generate_series(1,10) AS x;
-INSERT INTO tbl SELECT x, 2*x, NULL, NULL FROM generate_series(1,10) AS x;
+INSERT INTO tbl SELECT x, 2*x, NULL, NULL FROM generate_series(1,300) AS x;
explain (costs off)
select * from tbl where (c1,c2,c3) < (2,5,1);
select * from tbl where (c1,c2,c3) < (2,5,1);
+-- row comparison that compares high key at page boundary
+SET enable_seqscan = off;
+explain (costs off)
+select * from tbl where (c1,c2,c3) < (262,1,1) limit 1;
+select * from tbl where (c1,c2,c3) < (262,1,1) limit 1;
DROP TABLE tbl;
+RESET enable_seqscan;
CREATE TABLE tbl (c1 int,c2 int, c3 int, c4 box,
UNIQUE(c1,c2) INCLUDE(c3,c4));
[parent: 8fba397f0ca7]